feat: initial implementation

A first working, publishable version of colorsaver.nvim.

This plugin connects to the ColorScheme event to detect changes to the
colorscheme. Any time that changes, it saves the colorscheme's name to a
local file. In addition to that, it can watch that local file for
changes. This way, when one `nvim` process changes the colorscheme, all
other instances will automatically reload the colorscheme.

lua/colorsaver/logger.lua

@@ -0,0 +1,65 @@
+--- Logger module for neovim that provides a simple logging interface.
+-- @module Logger
+local Logger = {}
+Logger.__index = Logger
+
+--- Log levels with corresponding neovim's vim.log.levels.
+local log_levels = {
+  debug = vim.log.levels.DEBUG,
+  info = vim.log.levels.INFO,
+  warn = vim.log.levels.WARN,
+  error = vim.log.levels.ERROR,
+}
+
+--- Constructor for Logger object.
+-- @param min_level The minimum log level to output messages for.
+-- @param prefix A prefix to prepend to all log messages.
+-- @return A new Logger instance with specified level and prefix.
+function Logger.new(min_level, prefix)
+  local self = setmetatable({}, Logger)
+  self.min_level = log_levels[min_level] or log_levels.info -- Fallback to info level if unspecified
+  self.prefix = prefix or "Logger" -- Default prefix if none provided
+  return self
+end
+
+--- Sets the minimum log level.
+-- Only log messages at this level or higher will be output.
+-- @param min_level The minimum log level string ("debug", "info", "warn", "error").
+function Logger:set_level(min_level)
+  self.min_level = log_levels[min_level] or self.min_level -- Keep current level if the new level is invalid
+end
+
+--- Internal function to process the log message.
+-- @param level The log level of the message.
+-- @param message The log message.
+function Logger:_log(level, message)
+  if level >= self.min_level then
+    vim.notify(self.prefix .. ": " .. message, level)
+  end
+end
+
+--- Logs a message at DEBUG level.
+-- @param message The message to log.
+function Logger:debug(message)
+  self:_log(log_levels.debug, "DEBUG: " .. message)
+end
+
+--- Logs a message at INFO level.
+-- @param message The message to log.
+function Logger:info(message)
+  self:_log(log_levels.info, "INFO: " .. message)
+end
+
+--- Logs a message at WARN level.
+-- @param message The message to log.
+function Logger:warn(message)
+  self:_log(log_levels.warn, "WARN: " .. message)
+end
+
+--- Logs a message at ERROR level.
+-- @param message The message to log.
+function Logger:error(message)
+  self:_log(log_levels.error, "ERROR: " .. message)
+end
+
+return Logger